Plant embryos contain a large amount of linoleic acid which is an essential fatty acid, and also contain various water-soluble vitamins (chiefly vitamins B.sub.1, B.sub.2 and B.sub.6); various fat-soluble vitamins (chiefly vitamin E); and K, Na, Ca, Mg and other essential trace elements. Accordingly, plant embryos are used as a raw material for the production of embryo oil. Moreover, defatted plant embryos are used as a raw material for food, livestock feed, fertilizer and the like. Furthermore, they are properly roasted and used as health food. Excepting them, no remarkable use thereof has not been developed.
The present inventor has previously proposed a process for the extraction of embryo components which comprises extracting cereal embryos with hot water at about 70.degree. C. or above in the presence of an added starch hydrolase, boiling the extraction mixture without solid-liquid separation, and then subjecting the extraction mixture to solid-liquid separation (Japanese Patent Publication No. 1027/'80). However, when this extract is used to prepare embryo drinks, the sugars, proteins and other components contained therein precipitate as "sediment" with the lapse of time. This constitutes a serious obstacle to the preparation of drinks using plant embryos or defatted plant embryos as a raw material.
It is the primary object of the present invention to provide an embryo extract having high stability which extract is suitable for use in the preparation of drinks containing an abundance of components peculiar to plant embryos or defatted plant embryos (i,e., flavonoids, vitamins, minerals and the like) and having good storage stability.